1. Field of the Invention
The present invention relates to a method and an apparatus for high performance packet filtering in a communication network environment such as token ring, ATM, Ethernet, Fast Ethernet, Gigabit Ethernet and 10 Gigabit Ethernet or any other networking environment. In particular, the present invention relates to a packet filter and a method for filtering a packet that can be implemented in a network component, which may include discrete devices or which may be implemented on a semiconductor substrate such as a silicon chip.
2. Description of the Related Art
In networking applications, an incoming packet enters an ingress port of a network component, such as a switch. The network component processes the incoming packet and directs it to an egress port. In processing the incoming packet, the network component can examine the incoming packet on the ingress side, and can determine addressing and routing information to enhance network performance.
The network component can apply various pre-defined addressing and processing logic to the incoming packet, when examining the incoming packet on the ingress side therein. However if a customer wishes to have an action, which is not currently defined within the pre-defined actions table, performed on an incoming packet, the switch designer may have to redesigned or reconfigure the switch in order to add the newly desired actions. Alternatively, the packet may also be sent to a central processing unit (CPU) for processing by software and re-sent back to the network component. Thus, the switch may have to undergo an expensive complete chip production cycle from redesign, synthesis, validation and a new testing process in to add the additional features. In the case of software based modifications, this technique may severely impact the performance of the chip in processing that particular packet.
As the demand for higher speed and lower cost network components increases, so does the demand for an innovative system to meet such demand. Accordingly, a programmable field replacement action processing logic for a network component is important since it can benefit the communication network environment.